The present invention relates to an oil supplying device for an engine. In particular, the present invention relates to an oil supplying device for an engine which improves the sealing quality of an opening for a main oil pathway and which reduces seal failure. There is greater freedom in the placement position of an oil supply pathway. The pathway area for the oil supply pathway is ensured. The sealing quality of a secondary oil pathway is also improved.
An engine has an oil supplying device for lubricating sliding parts or cooling parts which reach high temperatures. The oil supplying device has an oil pump which is driven by a crank shaft of the engine. The oil pump suctions oil from an oil pool inside an oil pan and supplies the oil to a main oil pathway of a cylinder blocks. The oil in the main oil pathway is supplied to bearings of the crank shaft or to the inner surface of the cylinder. The oil lubricates as well as cools.
Referring to FIGS. 16-20, an oil supplying device for an engine of the prior art is shown. Referring to FIGS. 16-18, there is an engine 202, a cylinder block 204, a crank shaft 206, a lower case 208. Lower case 208 which supports crank shaft 206 on cylinder block 204 is attached to engine 202. An oil pan (not shown) is attached to lower case 208. A chain case 212 which covers a timing chain (not shown) is attached to cylinder block 204 and a side surface 210 along the crank shaft axis line A of lower case 208.
Referring to FIGS. 19 and 20, in oil supplying device 214 of engine 202, an oil pump 216 is attached inside chain case 212. Oil pump 216 is driven by crank shaft 206. A pump housing 220 is carried on a wall 218 of chain case 212. Oil pump 216 has an inner rotor and an outer rotor (not shown) which are capable of rotation and located internally within pump housing 220. A rotor plate 222 is attached so that it covers these rotors.
Oil pump 216 suctions and discharges oil within the oil pan. The discharged oil is supplied to main oil pathway 226 via an oil filter (not shown) and by secondary oil pathway 224 of cylinder block 204. Main oil pathway 226 opens at one end at opening 228 on side 210 in the crank shaft axis line A of cylinder block 204. The other end points towards the other side surface (not shown) of the crank shaft axis line A.
The oil in main oil pathway 226 is supplied by an oil supply pathway 234 to a block-side bearing surface 232 of block side bearing 230 of cylinder block 204. The oil is also supplied to the bearing surfaces of the crank shaft or a cam shaft or the like by an oil supply pathway not shown. The oil both lubricates and cools.
Oil supplying devices for an engine such as the one described above are disclosed in Japanese laid open patent publication numbers 61-185609, 3-51156, 1-102312.
In the oil supplying device disclosed in laid open publication number 61-185609, a crank shaft is supported by bearing caps which are each mounted on a plurality of journal walls on a cylinder block. The engine has a bridge member which links the plurality of bearing caps. A baffle plate is mounted on the underside of the bridge member as though to support the crank shaft and, the oil pooling.
In the oil supplying device disclosed in laid open publication number 3-51156, an oil-retaining/reinforcing plate is anchored to the lower end of a lower half frame which comprises the lower half of the crank case of an engine. An oil returning space is formed between the right and left walls of the lower half frame and both edges of the oil-retaining/reinforcing plate. An attachment boss piece for a suctioning pipe of an oil strainer is formed at this oil returning space.
In the oil supplying device disclosed in laid open publication number 1-102412, having a crank case side bearing, which supports the crank shaft, and the bearing cap as mating faces, the oil pathway which is supplied by a discharging area of the oil pump and an oil return pathway which returns to the suctioning area are connected. A relief valve is placed via the mating faces. An oil strainer is placed as a single body on the bearing cap via the suction pipes.
Referring to FIGS. 16-20, oil supplying device 214 has a main oil pathway 226 which opens at one end at opening 228 on one side surface 210 in the crank shaft axis line A of cylinder block 204. The other end points towards the other side surface of crank shaft axis line. Main oil pathway 226 is supplied by the oil discharged from oil pump 216. Referring to FIG. 16, opening 228 of main oil pathway 226 is closed off by screwing PT plug 236 into the opening.
Main oil pathway 228 has an inlet port 238 to a branch oil supply pathway 234 which connects to the block side bearing surface 232 of block side bearing 230 which supports crank shaft 206 of cylinder block 204.
Because of this, a part of inlet port 238 of branch oil supply pathway 234 which is formed on block side bearing 230 on side surface 210 in the crank shaft axis line A of cylinder block 204 can be blocked off by PT plug 236 which is screwed into opening 228 of main oil pathway 226.
PT plug 236 which is screwed into opening 228 of main oil pathway 226 can become inserted in deeper than is set due to tightening torque. Inlet port 238 of branch oil supply pathway 234 can be completely shut off, or else, due to over tightening, the area around opening 228 can become deformed and cracked. There is danger that the crack can result in failure or lowering of the sealing quality of main oil pathway 226.
The deformation around opening 228 of main oil pathway 226 due to PT plug 236 may also reduce the sealing quality between rotor plate 222 and secondary oil pathway 224, which is in neighboring contact with main oil pathway 226.
Oil pump 216 of oil supplying device 214 has a pump housing 220 on chain case 212. An inner rotor and an outer rotor (not shown) are located internally within pump housing 220 and are capable of rotation. A rotor plate 222 is attached so that it covers these rotors.
Referring to FIGS. 18 and 19, a guide pathway formation 240 is created on rotor plate 222. A strainer attachment flange 242 is formed on guide pathway formation 240. A guide pathway 246 is formed on guide pathway formation 240. Guide pathway 246 connects the oil pan to suction pathway 244 of oil pump 216. An oil strainer (not shown) is attached to strainer attachment flange 242.
But, because guide pathway formation 240 and strainer attachment flange 242 project towards the interior of rotor plate 222, a problem arises that chain case 212 must be made so that it does not interfere with block side bearing 230 on side 210 of crank shaft axis line A of cylinder block 204.
For this reason, chain case 212 projects a length L from side surface 210 in the crank shaft axis line A of cylinder block 4. The overall length of engine 202 becomes longer, and there is a disadvantage of increased weight.
Furthermore, referring to FIGS. 18 and 19, oil pump 216 of oil supplying device 214 has a rotor plate 222 attached to chain case 212. A relief pathway formation 248 is formed on rotor plate 222. Relief valve attachment part 250 is also formed on rotor plate 222. A relief pathway 254 which connects discharge pathway 252 of oil pump 216 to the oil pan is created in relief pathway formation 248. Relief valve 258 is attached to relief valve attachment hole 256 of relief valve attachment part 250.
Relief pathway formation 248 and relief valve attachment part 256 are placed so that it projects towards the interior of rotor plate 222. There is a problem in forming chain case 212 so that it does not interfere with block side bearing 230 on side 210 of crank shaft axis line A of cylinder block 204.
As a result, chain case 212 projects a distance L out from surface side 210 in the crank shaft axis line A of cylinder block 204. The overall length of engine 202 becomes longer, and there is a disadvantage of increased weight.